Conditions of the lower respiratory tract.pptx
- 1. Conditions of the lower respiratory tract. BY: MUTEGEKI ADOLF
- 2. 1. Asthma Definition: Asthma is a chronic inflammatory disorder of the airways characterized by episodes of reversible airway obstruction, bronchial hyper- responsiveness, and airway inflammation. This leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning Aetiology: Asthma's exact cause is not fully understood, but it is believed to result from a combination of genetic and environmental factors. Key contributors include: a) Genetic Predisposition: • Family history of asthma or atopy (allergic conditions like eczema, allergic rhinitis). • Specific genetic variants associated with immune response and airway function.
- 3. b) Environmental Factors: • Allergens: House dust mites, pollen, mold, pet dander, and cockroach droppings. • Irritants: Tobacco smoke, air pollution, strong odors, and chemical fumes. • Infections: Respiratory viral infections, particularly in early childhood. • Occupational Exposures: Certain chemicals, dusts, and gases in the workplace. • Dietary Factors: Obesity and a diet low in antioxidants may increase risk. C) Other Contributing Factors: • Exercise, particularly in cold air. • Emotional stress. • Gastroesophageal reflux disease (GERD).
- 4. Pathophysiology • Asthma involves complex interactions between airway inflammation, intermittent airflow obstruction, and bronchial hyperresponsiveness: a) Airway Inflammation • Inflammatory cells, including eosinophils, mast cells, T lymphocytes, and neutrophils, infiltrate the airway walls. • Release of inflammatory mediators such as histamine, leukotrienes, and cytokines leads to airway edema and mucus hypersecretion. b) Airflow Obstruction • Bronchoconstriction due to smooth muscle contraction. • Airway edema and mucus plug formation further narrow the airways. • This obstruction is typically reversible, either spontaneously or with treatment. c) Bronchial Hyperresponsiveness • Increased sensitivity of the airways to various stimuli, leading to exaggerated bronchoconstriction. • Chronic inflammation results in structural changes (airway remodeling), including thickening of the basement membrane and increased smooth muscle mass, which may contribute to persistent airflow limitation.
- 7. Clinical Presentations Asthma symptoms vary widely in frequency and severity. • Wheezing: A high-pitched whistling sound, particularly during expiration. • Shortness of Breath: Often worsens with physical activity, at night, or early in the morning. • Chest Tightness: A sensation of pressure or constriction in the chest. • Coughing: Typically dry, persistent, and may worsen at night or early morning. • Increased Respiratory Rate and Use of Accessory Muscles: During an asthma attack. • Note: Symptoms are often episodic, with symptom-free periods between attacks. However, in severe cases, symptoms may persist and lead to chronic breathlessness.
- 8. Differential diagnosis • Heart failure •Other causes of chronic cough •Bronchiolitis • Bronchiectasis
- 9. Investigations • Spirometry: • Measures lung function, including FEV1 (forced expiratory volume in one second) and FVC (forced vital capacity). • A reduced FEV1/FVC ratio that improves after bronchodilator administration suggests reversible airway obstruction. • Peak Expiratory Flow (PEF): • Simple tool for monitoring asthma control. Variability in PEF readings indicates poor control. • Bronchoprovocation Tests: • Methacholine or exercise challenge tests to assess airway hyperresponsiveness. • Allergy Testing: • Skin prick tests or serum IgE levels to identify specific allergens. • Chest X-ray: • Typically normal in asthma but can rule out other causes of symptoms (e.g., pneumonia, pneumothorax). • Blood Tests: • CBC mostly for Eosinophil count • Serum IgE levels may be elevated in atopic asthma.
- 10. Management General principles of management • The four essential components of Asthma Management: a) Patient education b) Control of asthma triggers c) Monitoring for changes in symptoms or lung function and d) Pharmacologic therapy. • Inhalation route is always preferred as it delivers the medicines directly to the airways; the dose required is smaller, the side-effects are reduced • Eg nebuliser solutions for acute severe asthma are given over 5-10 minutes, usually driven by oxygen in hospital
- 11. • Parenteral route is used only in very severe cases when nebulisation is not adequate. • Acute Asthma • Asthma attack is a substantial worsening of asthma symptoms. The severity and duration of attacks are variable and unpredictable. Most attacks are triggered by viral infections. • Not all features may be present. If the patient says they feel very unwell, listen to them!
- 12. Assessment of Severity Mild to moderate • Able to talk • Pulse < 110 bpm • Respiratory rate < 25 • Peak flow >50% of predicted or best SpO2 ≥ 92% Severe • Cannot complete sentences in one breath • Pulse 110 bpm • Respiratory rate >25 • Peak flow <50% of predicted or best SpO2 ≥ 92%
- 13. Life threatening (Adults and Children) •Silent chest, feeble respiratory effort, cyanosis •Hypotension, bradycardia or exhaustion, agitation • Reduced level of consciousness • Peak flow < 33% of predicted or best Arterial oxygen saturation < 92%
- 14. Management of asthma attacks A. Mild to moderate • Treat as an out-patient • Reassure patient; place him in a ½ sitting position • Give salbutamol Inhaler 2-10 puffs via a large volume spacer, Or 5 mg (2.5 mg in children) nebulisation • Repeat every 20-30 min if necessary • Prednisolone 50 mg (1 mg/kg for children) • Monitor response for 30-60 min. If not improving or relapse in 3-4 hours Refer to higher level
- 15. • If improving, send home with • Prednisolone 50 mg (1 mg/kg for children) once a day for 5 days (3 days for children) • Institute or step up chronic treatment • Follow up after 1-2 weeks • Instruct the patients on self-treatment and when to come back • Review in 48 hours • Do not give routine antibiotics unless there are clear signs of bacterial infection
- 16. B. Severe Attack •Patients with severe asthma need to be referred to HC4 or hospital after initial treatment. •Admit patient; place him in a ½ sitting position •Give high flow oxygen continuously, at least 5 litres/minute, to maintain the SpO2 ≥ 94% if available •Give salbutamol Inhaler 2-10 puffs via a large volume spacer, Or 5 mg (2.5 mg in children) nebulization. Repeat every 20- 30 min if necessary during the 1st hour
- 17. • Prednisolone 50 mg or f Or hydrocortisone 100 mg (children 4 mg/kg max 100 mg) IV every 6 hours until patient can take oral prednisolone • Monitor response after nebulisation • If response poor, pratropium bromide nebuliser 500 micrograms every 20- 30 min for the first 2 hours then every 4-6 hours • Or Aminophylline 250 mg slow IV bolus if patient is not taking an oral theophylline • Alternatively, if symptoms have improved, respiration and pulse settling, and peak flow >50% • Step up the usual treatment and continue with prednisolone to complete 5 days of treatment • Review within 24 hours • - Monitor symptoms and peak flow • Arrange self-management plan
- 18. Life threatening • Arrange for immediate hospital referral and admission First aid • Admit patient; place him in a ½ sitting position • Give high flow oxygen continuously, at least 5 litres/minute, to maintain the SpO2 ≥ 94% if available • Give salbutamol Inhaler 2-10 puffs via a large volume spacer Or 5 nebulisation • Repeat every 20 min for 1 hour
- 19. • Hydrocortisone 100 mg IV stat or prednisolone 50 mg • Ipratropium bromide nebuliser 500 micrograms every 20- 30 minutes for the first 2 hours then every 4-6 hours • Monitor response for 15-30 minutes • If response is poor, Give Aminophylline 250 mg slow IV bolus If patient is not taking an oral theophylline Note: The use of aminophylline and theophylline in the management of asthma exacerbations is discouraged because of their poor efficacy and poor safety profile
- 20. Chronic Asthma • General principles of management • Follow a stepped approach Before initiating a new drug, check that diagnosis is correct, compliance and inhaler technique are correct and eliminate trigger factors for acute exacerbations. • Start at the step most appropriate to initial severity Rescue course • Give a 3-5 days “rescue course” of prednisolone at any step and at any time as required to control acute exacerbations of asthma at a dose of 40-60 mg daily for up to 3-5 days.
- 21. Stepping down •Review treatment every 3-6 months •If control is achieved, stepwise reduction may be possible •If treatment started recently at Step 4 (or contained corticosteroid tablets, reduction may take place after a short interval; •In other patients 1-3 months or longer of stability may be needed before stepwise reduction can be done
- 22. STEP 1: Intermittent asthma •Intermittent symptoms (< once/week) •Night time symptoms < twice/month •Normal physical activity •Occasional relief bronchodilator: Inhaled short-acting beta2 agonist e.g. salbutamol inhaler, 1-2 puffs (100-200 micrograms) •Move to Step 2 if use of salbutamol needed more than twice a week or if there are night-time symptoms at least once a week.
- 23. STEP 2: Mild persistent asthma • Symptoms > once/week, but < once/day • Night time symptoms > twice/month • Symptoms may affect activity Regular inhaled preventer therapy • Salbutamol inhaler 1-2 puffs prn • Plus regular standard-dose inhaled corticosteroid, e.g. beclomethasone 100-400 micrograms every 12 hours. • Assess after 1 month and adjust the dose prn • Higher dose may be needed initially to gain control • Doubling of the regular dose may be useful to cover exacerbations
- 24. •STEP 3: Moderate persistent asthma • Daily symptoms •Symptoms affect activity •Night time symptoms > once/week Daily use of salbutamol Salbutamol inhaler 1-2 puffs prn up to 2-3 hourly Usually 4-12 hourly •PLUS beclomethasone inhaler 400-1000 micrograms every 12 hours •In adults, also consider 6-week trial with Aminophylline 200 mg every 12 hours
- 25. STEP 4: Severe persistent asthma • Daily symptoms • Frequent night time symptoms • Daily use of salbutamol Regular corticosteroid tablets plus Regular high-dose beclomethasone (as in Step 3) • Plus regular prednisolone 10-20 mg daily after breakfast Note: If inhaler not available, consider salbutamol tablets 4 mg every 8 hours
- 26. Prevention • Primary Prevention: • Avoid exposure to tobacco smoke and environmental pollutants during pregnancy and early childhood. • Breastfeeding may reduce the risk of developing asthma. • Secondary Prevention: • Early identification and treatment of allergic conditions. • Avoidance of known triggers in sensitized individuals. • Regular use of controller medications to maintain control and prevent exacerbations. • Tertiary Prevention: • Educating patients on early recognition of worsening symptoms and adherence to treatment. • Regular follow-up with healthcare providers to monitor asthma control and adjust treatment as needed.